Mattermost 目标: 非 ASCII 字符出错 (缺少 .encode("utf-8"))

Summary: In redash/destinations/slack.py:53, json_dumps(payload).encode("utf-8") is used, and Russian letters work. In redash/destinations/mattermost.py:47, json_dumps(payload) is used without .encode("utf-8"), and non-ASCII characters are broken. The fix is to add .encode("utf-8") in mattermost, as already done in slack. You can also provide the line numbers: